SUBCON 2007

Submarine Technologies for New Mission Scenarios

Hans Karr

The international “Submarine Conference (SUBCON) 2007” took place in Kiel / Germany with 400 attendees from at home and abroad, among them delegates from 26 navies. After 1995, 1999, and 2003 the capital of the State of Schleswig-Holstein was now for the fourth time the venue of this successful conference series. Organizers of the renowned meeting were the Submarine Division of ThyssenKrupp Marine System (TKMS), MAN Ferrostaal, and Marine Force International. The Submarine Division of TKMS comprises the shipyards Howaldtswerke-Deutsche Werft (HDW) in Kiel , Nordseewerke (NSWE) in Emden , Kockums in Malmö and Karlskrona ( Sweden ), and Hellenic Shipyards in Skaramanga near Athens ( Greece ). The organizers of the 2007 SUBCON have been collaborating in the field of non-nuclear submarines for many years already and are worldwide market leaders here. In the past 45 years the shipyards of the Submarine Division of TKMS could enter 169 orders for submarines into their books for 22 navies.
Key affair of the 2007 SUBCON was the exchange of ideas and experiences between industry and submarine-operating navies and/or those, which would like to introduce submarines into their fleets. Based on the mission experiences of the navies and the latest technical developments the conference indicated and discussed perspectives for a continued cooper­ation. In the technical field more than 40 presentations on new submarine designs, ship engineering and propulsion technology, weapon, detection and communication systems as well as rescue means were on the agenda. The program was rounded off with a tour of submarine installations of the German Navy in Eckernfoerde and a visit to the submarine production facilities at HDW with a conjoint exhibition by the maritime supply industry. The meeting was held under the motto: “Submarines in a New World Order”. Patron of the 2007 SUBCON was the Federal Minister of Defence, Dr. Franz Josef Jung, on whose behalf the Parliamentary State Secretary Thomas Kossendey opened this technical conference.

Submarines in Project Planning Phase and under Construction

Class 212A Submarines

With the Class 212A submarines the German and Italian navies have a weapon system of high technical performance in their inventory, which fully meets the requirements of the future. Innovative developments were applied as high technology on an international scale for the first time. Almost concurrently with the SUBCON it was possible to demonstrate for the first time the mutual interoperability between German and Italian submarines of the 212A class in a torpedo-launching phase in the Bay of Tarentum . The submarine class 212A does no longer deserve to be designated “conventional”, the more appropriate term is rather “non-nuclear”. The German submarine U 32 impressively proved the potential of the fuel cell technology in April 2006, which was traveling submerged without outside air supply on a two-week redeployment run to the Mediterranean . So far only nuclear-powered submarines were capable of such a performance. The Class 212A fills thus the gap between the conventional diesel-electrically powered submarines and the nuclear subs. After the Budget and Defence Committees of the German Bundestag (Lower House of Parliament) had agreed to the procurement a few days before, the contract between the consortium “ARGE 2nd Batch 212A” and the Federal Office for Defence Technology and Procure­ment was signed on 22 September 2006. The consortium consists of the Howaldtswerke Deutsche Werft (HDW) and Nordseewerke (NSWE), which are part of the TKMS shipyard combine. Production start of the first of two new submarines of the 212A Class for the German Navy was with the HDW Shipyard in Kiel/Germany on 21 August 2007.
The second batch of the 212A Class is based on the already proven overall design of the first four boats. Like their predecessors they will be made of anti-magnetic steel and equipped with an air independent propulsion (AIP) on the basis of the fuel cell. Adapted to the future mission requirements of the German Navy they have extended capabilities compared to the first batch. In particular, modern communication means and command control systems allow the participation in network enabled warfare (NEW) and close the gaps still existing in the first batch in respect to command capability. Enhanced detection ranges improve their possibilities with regard to intelligence and reconnaissance. The delivery of the units is scheduled for 2012 and 2013. The investment volume for the two submarines U 35 and U 36 amounts to more than 820 million euros. Jobs as well as defence technology core capabilities of the German shipyard industry and their subcontractors/supply companies will be secured that way.

U 214 Submarines

The 214 Class is a modern oceangoing submarine based on the 209 Class, which had its successful start by an order from Greece 35 years ago. The experiences gathered in the construction of this class over many years as well as the technological development, which led to the 212A Class resulted in the devel­opment of this new type of boat. When formulated in a simple equation, the design formula would read as follows: U 214 = U 209 + U 212. As an innovative element the AIP system with the fuel cell deserves a special mention. The Greek Navy will acquire four boats of which the first one will be build by HDW in Kiel and three by way of material package deliveries and an extensive technology transfer at the Hellenic Shipyard in Skaramanga near Athens. The PAPANIKOLIS has mean­while successfully ended the sea trials and is presently waiting in Kiel for the takeover by the Greek customer.
The South Korean Navy has also decided in favor of this type and has ordered three units which will be build at the Hyundai Shipyard in Ulsan in South Korea , however. HDW will deliver the material packages for them. The commissioning is planned to be completed by 2009. Other navies in the world are also interested in the Class 214.

U 209PN Submarine

Moreover, the former German submarine consortium consisting of the HDW and NSWE shipyards and the Ferrostaal AG had the possibility to conclude a contract with the Portuguese Navy on the construction and delivery of two Class 209PN submarines. This boat class is particularly tailored to the requirements of the Portuguese Navy and is considered a variant of the Class 214. The subs are to be delivered in 2010 and 2011.

DOLPHIN Class

The Israeli Navy has, as the sixth navy in the world, also decided in favor of the air independent propulsion and ordered two modified boats of the DOLPHIN Class with fuel cell. The delivery of the subs is expected to occur after 2010.

U 209-1400mod Submarine

The production of the first of three submarines of the 209-1400mod Class for the South African Navystarted at HDW Shipyard on 22 May 2001. These submarines are the most sophisticated version of the conventional 209 Class. The procurement of the three units is part of a comprehensive modernization program of the South African Navy. Two subs of the MANTHATISI and CHARLOTTE MAXEKE Class have been handed over already and have mean­while sailed to their home country. The third boat, the QUEEN MODJADJI, is to follow in November 2007. The 209 Class comprises thus a total of 61 constructed units.

U 210mod Submarine

The novelty of the developments presented at the 2007 SUBCON was the 210mod Class, a single-hull submarine with a length of 56 m and a displacement of about 1,000 tons. It is thus clearly smaller than the other submarines currently offered at home and abroad. This compact and seaworthy submarine meets the standards of present and future operational requirements. Target group of this boat, which is equipped with eight torpedo tubes/containers, are newcomers and navies that cannot im­plement complex submarine classes due to budgetary constraints. The U 210mod is also an alternative to expensive modernization measures of submarines that are getting on in years. It rounds down the portfolio of the TKMS Submarine Division with another contemporary and modern submarine type.

The development of the successor boats for the GOTLAND Class (A 19) started in Sweden under the project designation VIKING in the 1990s already as a trinational project which came to a standstill after Norway left it and when Denmark gave up the submarine component altogether. The Swedish Kockums Company is presently developing on the basis of VIKING the new A 26 submarine design as a successor project. The boat has a length of 62 m and an underwater displacement of approximately 1,650 tons. The further development of the Mk II in use on the GOTLAND Class is now put to use with the advanced Mk III Stirling engine as air independent propulsion. A pressure-proof bulkhead offers docking possibilities for rescue vehicles. The well-proven pressure hull diameter of 6.2 m of the GOTLAND Class is to be maintained in order to be able to apply solutions for both the A 26 and for a modernization program for A 19. The design includes a universal bus system for the combat direction system, sonar and ship engineering systems like automation and communication. A diver airlock hatch and an autonomous under water vehicle (AUV) have been realized in the form of a supercaliber weapon tube in the area of the four torpedo tubes/containers.

Air Independent Submarine Propulsions

The principle of the fuel cell is called electrical energy by direct input. The accompanying reactants hydrogen and oxygen are converted in a direct way to electrical current (DC). The operating principle corresponds to the reversal of the water electrolysis with the reaction product resulting from that being only pure water. The quiet fuel cell works under low pressure (< 3 bar) with an operating temperature of about 80° Celsius and achieves a thermodynamic efficiency of approximately 65 percent. Another system, the Stirling en­gine, was developed at the Kockums Company, a subsidiary of HDW, and was first installed on the NAECKEN Submarine in 1988 already. The three submarines of the GOTLAND Class were equipped with that engine in the 1990s. By applying this principle, heat is being converted into mechanical energy in a thermodynamic circular process. This is achieved by heating and cooling of an operating helium gas in a combustion chamber. A generator is operated for producing electric power using the extracted kinetic energy. Diesel fuel and accompanying liquid oxygen is combusted in that process. The combustion products are cooled down from 750° Celsius and released to outboard.
The psychrocycle diesel engine is a development of NSWE and was tested in practice in the ex-U1 submarine decommissioned by the German Navy. The exhaust gases of the diesel engine are cooled down, purified from CO? in seawater and re-supplied to the engine by addition of oxygen. The CO? absorbed in the seawater is pumped to outboard. The system meets the requirements in respect to acoustic signatures and has proved reliable in operation. Essential advantages are the low acquisition and operating costs. Here, too, the oxygen necessary for the operation is carried along in liquid form.
As the only enterprise in the world TKMS has and can thus offer fully tested, non-nuclear, air independent submarine propulsion systems. The fuel cell propulsion was so far possible to be contracted on 19 submarines in six navies. Six units of the 212A Class are already in service with the German and Italian navies. Within the scope of modernization measures three boats of the Greek POSEIDON Class are also going to get fuel cells.

Submarine Armament and Equipment

In its capacity as a multipurpose weapon the fence and Attack System (IDAS) will lend submarines completely new capabilities in future. The IDAS is a light missile flying in the high subsonic range with infrared guidance. The image of the seeker head is transmitted via fiberoptic connection to the operator’s console. It allows to influence the effect of the weapon in the target and to determine the point of impact with utmost precision. It will be employed from a weapon-launching container, which is embedded in a torpedo tube. IDAS is a defence system against antisubmarine helicopters, which possesses additional capabilities for engaging small maritime targets and coastal shore objects. Apart from the possibility for self-defence it gives the submerged submarine the capability for an escalating weapons effect. Contractor on the industrial side is the ARGE IDAS Consortium, which is composed of the following companies: Diehl BGT Defence (missiles), the Howaldtswerke Deutsche Werft (system integration), and Kongsberg (weapon delivery systems).
Diverse systems have meanwhile been developed as defence means against torpedo threats. High acquisition range and high detection probability are the most important requirements. According to the current state of technology these capabilities are possible to be achieved by use of very good acoustic sensors. A quickly and precisely working electronic evaluation process is another indispensable necessity. In principle, two basically different defence concepts are being applied here. To date, the most common ones are softkill measures. In danger situations the threatened submarine is masked by means of noise and signal generators. More effective, however, are meanwhile hardkill measures, which aim at destroying the attacking torpedo.
A softkill defence system is available with the Containerized Integrated Reaction Countermeasures Effectors (CIRCE), which were developed by HDW and the Italian company Whitehead Alenia Siste­mi Subacquei (WASS) in cooperative action. The system consists of foldout launching containers with ten effectors each which, after ejection, deflect as mobile or stationary decoys approaching torpedoes from the actual target by means of integrated jamming and deception functions. Jamming by means of broadband noise interrupts the target contact of the attacking torpedo. In a subsequent phase the effectors divert the torpedo by way of a realistic target mock up far enough to make it impossible for it to reach the submarine. Torpedo acquisition and activation of the system is effected via the submarine’s sonar systems. On the new South African submarines of the 209/1400mod Class, CIRCE is installed in the forward ship area between the pressure hull and outer shell.
The Israeli Rafael Company devel­FLAME. oped the Reactive Expendable Acoustic Torpedo Decoy (SCUTTER), which is also a softkill system of versatile self-propelled decoys. SCUTTER can be employed against acousti­cally active and passive homing torpedoes. The decoy is employed in pairs and cruises after its launch in a self-acting way to a position in a preset depth where it will then function fully automatically. A data bank contains numerous noise and reference patterns for the identification of attacking torpedoes. By repeated re­ciprocal attacks on the decoy pair the torpedoes are to gradually die out. In this phase, the submarine is in the depth in the acoustic shadow of the decoys and is thus not detectable by the torpedo.
The SEA SPIDER by Atlas Elektronik is a small, highly mobile and quickly cruising anti­torpedo torpedo. The hardkill system can be employed from fixed or foldout launching con­tainers installed between pressure hull and outer shell. Another possibility is the employment through weapon containers embedded in the torpedo tube. The projectile is propelled by an underwater rocket engine. The built-in sonar works in active, passive and intercept modes. SEA SPIDER is designed for short and medium operational ranges. It is launched automat­ically via the Combat Direction System of the submarine as soon as this system identifies a torpedo attack. The operator can switch off the automatic control via a veto function.
The Gabler Maschinenbau Company presented an innovative way for the employment of submarines in the new threat scenarios. With the modular TRIPLE M multipurpose mast a system was developed which allows to flexibly equipping a submarine for a large number of tasks in a mission-specific mode. Equipped with a recoilless small-caliber automatic gun it is possible to engage in periscope depth targets up to a distance of 2,000 m. Alternatively the pressure-proof container is also useable for accommodating reconnaissance drones. An additional use can be provided by the installation of antennas for signal intelligence (SIGINT).
The CALLISTO communication buoy is also a development by the Gabler Company. It is a hoistable device with a hydrodynamic floating body, which can be brought to the surface by means of a winch system and then towed along. With CALLISTO it is possible to ensure the communication from the deeply submerged traveling submarine in both the re­ceiving and transmitting modes. The frequency bands for UHF, VHF, HF, SATCOM, and GPS are covered. All communication and sensor signals are transmitted into the boat through parallel multiple fibers in the towing cable. First tests in practical use have already been made on a submarine of the 206A Class. Prototype antennas have proven well within the scope of a long duration test in the extend­ed area of operations of the German Navy. In April 2007 it was possible to contract CALLISTO for the second batch of submarines of the 212A Class. The Atlas Elektronik Company has presented the new sonar concept of a planar lateral antenna EFAS (Expanded Flank Array Sonar) at the 2007 SUBCON for the first time. EFAS operates in the deep to medium-frequency range (10 Hz to 5 kHz) and shows a clear performance improvement in comparison with the present flank array sonar. This becomes apparent in improvements in the detection range, the detection probability, and in the target separation. EFAS represents a possibility for a future modernizing of existing flank array systems and will be installed on the U 212A subs, 2nd batch. Research and development is conducted by use of the Flow Noise Analysis and Measurement Equipment (FLAME).

Cutting Edge in Defence Technology

The 2007 SUBCON was all in all an informative conference covering the extensive field of submarine technology. It showed that the German shipyard and supply industry could offer high defence technology on a global scale. The systems addressed in this article represent only a very small extract from this offer, which was just not possible to be presented in its total extent for reasons of space. The international conference made also clear that modern conventional submarines, especially when equipped withAIP, are effective naval warfare means in both the old role as a means of attack against surface targets and in the changed threat and mission scenarios in the new millennium as well. Due to their incalculability they pose a constant deterrence and contain permanently enemy forces in all three dimensions. They are difficult to discover and well suited to detect, pursue and engage enemy forces. When equipped with missiles they are additionally capable of attacking shore targets. Moreover, they can lay mines and release attack swimmers of the maritime Special Forces.
For the TKMS submarine shipyards and the supply industry the successes in the export business and the handling and processing of the contracted construction program results in a full capacity utilization of the production facilities and security for thousands of jobs in the years to come. With the German Navy’s demand for sub­marines alone it would not be possible, however, to maintain the defence technological core capabilities and professional competence in the highly technical naval shipbuilding sector and the level of employment of specialist personnel.

By Commander (GE N) Hans Karr, Participant in SubCon 2007.